Peristaltic pumps are well known and widely used in applications where contamination of the fluid being transported is undesirable or unacceptable. In such a peristaltic pump, the fluid is contained in a compressible tube that is repeatedly compressed by rollers or the like, thereby expelling a precisely determinable portion of liquid from the end of the tube. Because of the ability to handle liquids in a precise and uncontaminated manner, such pumps have found wide application in the pharmaceutical and medical industries.
The compression of the tube in the peristaltic pump may be abrupt, so there is often an eruption or surge of fluid from the pump, which can result in dripping and splashing of the liquid. In circumstances where precise delivery of liquid is required, for example, in dispensing liquid medications into uni-dose containers, such dripping and splashing is intolerable. The particular applications of the peristaltic pump that require precise and uncontaminated delivery of liquid also dictate that any reusable parts, particularly nozzles and the like, used in conjunction with such fluids must be easily disassembled for cleaning and/or sterilization purposes. The same applications dictate that the surfaces be generally "clean", that is, that they are generally smooth and contain few niches or crannies that can deter easy cleaning.